Improvement in dental chairs



No. 61,553. PATENTED DEC. 19, 1865. I W. M. BUTLER.

DENTAL CHAIR.

UNITED STATES PATENT- OFFICE.

' WM. M. BUTLER, OF SAN FRANCISCO, CALIFORNIA.

IMPROVEMENT IN DENTAL CHAl RS.

' Specification forming part of Letters Patent No. 51,563., dated December 19, 1865.

To enable others skilled in the art to make and use my chair, I will proceed to describe its construction and operation, and referring to the drawings, in which the same letters indicate like parts in each of the figures.

Figure 1 represents a side elevation. Fig. 2 is a sectional view of the head-rest. Fig. 3 is a. view of a segment which gives the chair a side motion.

The nature of my invention consists in providing a chair so arranged that it can be adjusted to any position desired by means of a lever and spring, which may be operated by the foot or hand, giving a backward or forward or side position at any angle desired.

My invention also relates to an adjustable head-rest, consisting of joint, slide, ratchetwheel, and set-screws; also, to the elevating and lowering the seat and foot roll or board by means of beveled gears.

In the accompanying drawings, A is the body of the chair, made of wood or other ma terial.

B is the seat, supported or raised and lowered .by the screw 0, the upper end of which is brought into contact with the seat and moved by the beveled gear D and crank E.

F, Figs. 1 and 3, is a lever moving the pin which holds the segment G in place by passing into holes arranged at intervals along the edge, and kept in place by the spiral spring H, and having its axis by means of lugs or hinges a b upon the segment M. By this device the oper \tor is enabled to give the chair the desired side or tilting position without the danger of throwing the patient out, as the pin Y, to which is attached the spiral spring, flies into each hole in the segment G in passing.

I is a crank moving the gear J, by this means the screw Kthus elevating or depressing the foot-rest L.-

M is another segment of a circle, turning on its axis N, with a pin, Z, holding it by means of the spiral spring 0, and moved by the footlever P. This gives a forward-and-hackward motion to the chair and prevents the liability to accident by means of the spiral spring and pin, in the same manner as in the segment G, the pin moving or passing up through a segment of a circle, 0, extending across the pedestal d, and upon which the segment M has its base, should the foot of the operatorslip while adjusting the position of the chair.

In the axis N, segment M, I make a slot. This is for the purpose of giving play to the screw when the side position of the patient is required.

R, Figs. 1 and 2,isa head-rest moving up move it up and down, placed in'the back of the chair.

X is a ratchet working in a sleeve, Q, and kept in place by means of the set-screw W, which gives the head-rest a backward-and-forward motion.

The base or pedestal of my chair I make of iron or other material. The feet are orna'men ted, if desired. The frame is upholstered according to taste.

Some of the advantages of my chair over those ordinarily constructed may be enumerated as follows, viz: It is frequently necessary to change the position of the patient, especially when operatipg about the head and eyes, as when filling the back teeth. By inclining the head the saliva is carried to the other side of v operator the advantage of the position of applying strength when and where it is most needed. My chair has also been found to be very ble any person useful when operating about the eyes, as well desire to secure by and their lever-stops, in combination with the chair-seat and pedestal, in the manner and for the purposes set forth.

In witness whereof I have hereunto setmy hand and afiixed my seal, at San Francisco, this 1st day of April, A. D. 1865. 4

WILLIAM M. BUTLER. L. sj

Witnesses:

O. W. M. SMITH, W. D. R001. 

